Method for potting a stator

Abstract

The present invention relates to a method for potting a stator of an electric machine, including:—introducing an expandable, preferably elastically deformable, non-metallic shell in a non-expanded state into the stator,—expanding the shell,—pouring a resin around the shell, inside the stator,—retracting and removing the shell after the resin has set.

1 - 16 . (canceled) 
     
     
         17 . A method for potting a stator of an electric machine, comprising the steps consisting in:
 introducing an expandable, non-metallic shell in a non-expanded state into the stator,   causing the shell to expand,   pouring a resin around the shell, inside the stator,   retracting and removing the shell after the resin has set, the outer surface of the shell having a roughness less than or equal to 5 μm.   
     
     
         18 . The method according to  claim 17 , the shell being made of an elastically deformable synthetic material. 
     
     
         19 . The method according to  claim 18 , the shell comprising or being made of silicone, of rubber or of polyurethane. 
     
     
         20 . The method according to  claim 17 , the expansion of the shell being caused by an expansion tool arranged inside the latter. 
     
     
         21 . The method according to  claim 20 , the expansion tool being configured to convert a tightening torque into an expansion of the shell. 
     
     
         22 . The method according to  claim 21 , the expansion tool comprising a tightening screw and a mandrel co-operating with two abutments, the separation of which is modified by the tightening screw. 
     
     
         23 . The method according to  claim 22 , the mandrel comprising segments, one in every two of which are linked at one end. 
     
     
         24 . The method according to  claim 20 , the expansion tool comprising a body passed through by a coil in which a fluid circulates. 
     
     
         25 . The method according to  claim 17 , a volume for receiving the resin, defined between the shell and the stator, being closed at the bottom by a blocking plate. 
     
     
         26 . The method according to  claim 17 , comprising the fitting onto the stator of at least one plug for blocking any passage of wires. 
     
     
         27 . The method according to  claim 17 , the outer surface of the shell having a roughness less than or equal to 3 μm. 
     
     
         28 . The method according to  claim 17 , the shell being obtained by compression. 
     
     
         29 . The method according to  claim 17 , at least one inscription being made by molding on the resin, notably using a relief inscription present on a blocking plate or a blocking plug arranged at a wire passage to a terminal box of the machine. 
     
     
         30 . An installation for implementing the method as defined in  claim 17 , this installation comprising:
 an expandable, elastically deformable, non-metallic shell,   a tool for expanding the shell.   
     
     
         31 . The installation according to  claim 30 , the tool being an expandable mandrel. 
     
     
         32 . The installation according to  claim 30 , the installation comprising a plate for blocking the stator at one end. 
     
     
         33 . The installation according to  claim 30 , the installation comprising at least one plug for blocking a wire passage opening from the winding to a terminal box of the machine. 
     
     
         34 . A stator of an electric machine, notably obtained by implementing the method as claimed in  claim 17 , comprising:
 a magnetic frame comprising teeth separated by notches,   a winding arranged in the notches of the magnetic frame,   a central passage for the rotor, defined by the teeth and by a resin potting, the roughness of the radially inner surface of the resin, between the teeth, being less than or equal to 5 μm, or better, 3 μm.   
     
     
         35 . The stator according to  claim 34 , the radially inner surface of the resin potting extending set back from the teeth. 
     
     
         36 . The stator according to  claim 34 , the radially inner surface of the resin potting being without any traces of machining.